feat(ui): unify resource headings with responsive action menus

Add responsive overflow handling and dedicated action menus for application,
service, database, and server headings, while improving upgrade and email
settings flows and returning 404s for missing deployment environments.

tests/Feature/ResourceHeadingOverflowTest.php

@@ -0,0 +1,36 @@
+<?php
+
+it('collapses resource header actions only when the top bar cannot fit them', function () {
+    $overflow = file_get_contents(resource_path('views/components/resource-heading-overflow.blade.php'));
+    $css = file_get_contents(resource_path('css/app.css'));
+
+    expect($overflow)
+        ->toContain('data-resource-heading-overflow')
+        ->toContain('measureInlineWidth')
+        ->toContain('availableWidth')
+        ->toContain('reserved += 200')
+        ->toContain('hudSiblings')
+        ->toContain('Actions')
+        ->toContain('listbox-panel top-full! right-0! left-auto!')
+        ->toContain("\$dispatch('resource-actions-toggled', { open })");
+
+    expect($css)
+        ->toContain('.resource-heading-overflow-items')
+        ->toContain('.resource-heading-overflow-items.is-measuring')
+        ->toContain('.resource-heading-overflow.is-collapsed');
+});
+
+it('uses the overflow group for application, service, database, and server desktop actions', function () {
+    $files = [
+        resource_path('views/livewire/project/application/heading.blade.php') => 'application-desktop-actions',
+        resource_path('views/livewire/project/service/heading.blade.php') => 'service-desktop-actions',
+        resource_path('views/livewire/project/database/heading.blade.php') => 'database-desktop-actions',
+        resource_path('views/livewire/server/navbar.blade.php') => 'server-desktop-actions',
+    ];
+
+    foreach ($files as $path => $id) {
+        expect(file_get_contents($path))
+            ->toContain('<x-resource-heading-overflow')
+            ->toContain($id);
+    }
+});